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June 16th, 2026 08:31
PCIe-Training error
I have Dell latitude 3420. My laptop used to work for 5 minutes perfectly fine and then automatically showed Your device ran into an error and needs to restart with BSOD messages like these.
UNEXPECTED_STORE_EXCEPTION
Kmode exception not handled 0x1E
Critical_process_died
So i ran a diagnostic test by pressing the f12 during the boot. The test result showed
PCIe-Training warning on device PCI tag-2B00 VendorID-1587 DeviceID-5015 SVid-1587 SDid-5015 Link Degraded, maxWidth = x 4 negWidth = x 1
What is the issue here?
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anne_droid
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June 16th, 2026 10:23
Hi
The internet reports ...
That warning means the PCIe link negotiated only x1 lanes even though the device reports x4 capability, so the fix is usually to check slot/cable compatibility, update BIOS/firmware, and then retrain or reseat the device if needed.
Please can you confirm the Make Model and OS, along with any configuration details like touch screen, backlit keyboard, SFF or tower etc etc.
Just give what details you can,that are non-personal.
Akc2217
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June 16th, 2026 10:43
@anne_droid it's a dell latitude 3420 p144g201 with Microsoft windows 11 pro, no touchscreen and no backlit keyboard
mazzinia_
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June 16th, 2026 12:25
did you have this problem before installing this month windows updates ?
Akc2217
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June 16th, 2026 17:11
@mazzinia_ No, i didn't have the PCIe error
mazzinia_
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June 16th, 2026 18:47
@Akc2217 check this
https://www.dell.com/community/en/conversations/supportassist-for-pcs/bsod-random-reboots-may-2026-dell-updates-dell-support-assist-probable-cause/6a017bde657052398888e805
you can check what you have installed / remove what you don't need.
2nd option is to rollback the monthly windows update, then start digging the error logs to find out with calm which software is misbehaving.
(edited)
johnfleck
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June 27th, 2026 03:42
I followed your suggestion and checked/uninstalled recent installs and even rolled back the latest Windows update, but the issue is still happening. The BSODs (UNEXPECTED_STORE_EXCEPTION, KMODE_EXCEPTION_NOT_HANDLED, CRITICAL_PROCESS_DIED) keep coming back, and the Dell diagnostics still show the PCIe-Training warning with the link degraded (x4 → x1).
mazzinia_
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June 27th, 2026 08:59
@johnfleck ach. it could be the nvme drive having issues to its internal controller
(edited)